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git-format-patch(1) Manual Page
NAME
git-format-patch - Prepare patches for e-mail submission
SYNOPSIS
git format-patch [-k] [(-o|--output-directory) <dir> | --stdout]
[--no-thread | --thread[=<style>]]
[(--attach|--inline)[=<boundary>] | --no-attach]
[-s | --signoff]
[--signature=<signature> | --no-signature]
[--signature-file=<file>]
[-n | --numbered | -N | --no-numbered]
[--start-number <n>] [--numbered-files]
[--in-reply-to=<message-id>] [--suffix=.<sfx>]
[--ignore-if-in-upstream] [--always]
[--cover-from-description=<mode>]
[--rfc[=<rfc>]] [--subject-prefix=<subject-prefix>]
[(--reroll-count|-v) <n>]
[--to=<email>] [--cc=<email>]
[--[no-]cover-letter] [--quiet]
[--commit-list-format=<format-spec>]
[--[no-]encode-email-headers]
[--no-notes | --notes[=<ref>]]
[--interdiff=<previous>]
[--range-diff=<previous> [--creation-factor=<percent>]]
[--filename-max-length=<n>]
[--progress]
[<common-diff-options>]
[ <since> | <revision-range> ]
DESCRIPTION
Prepare each non-merge commit with its "patch" in
one "message" per commit, formatted to resemble a UNIX mailbox.
The output of this command is convenient for e-mail submission or
for use with git am.
A "message" generated by the command consists of three parts:
-
A brief metadata header that begins with From <commit>
with a fixed Mon Sep 17 00:00:00 2001 datestamp to help programs
like file(1) to recognize that the file is an output from this
command, fields that record the author identity, the author date,
and the title of the change (taken from the first paragraph of the
commit log message).
-
The second and subsequent paragraphs of the commit log message.
-
The "patch", which is the diff -p --stat output (see
git-diff(1)) between the commit and its parent.
The log message and the patch are separated by a line with a
three-dash line.
There are two ways to specify which commits to operate on.
-
A single commit, <since>, specifies that the commits leading
to the tip of the current branch that are not in the history
that leads to the <since> to be output.
-
Generic <revision-range> expression (see SPECIFYING
REVISIONS section in gitrevisions(7)) means the
commits in the specified range.
The first rule takes precedence in the case of a single <commit>. To
apply the second rule, i.e., format everything since the beginning of
history up until <commit>, use the --root option: git format-patch
--root <commit>. If you want to format only <commit> itself, you
can do this with git format-patch -1 <commit>.
By default, each output file is numbered sequentially from 1, and uses the
first line of the commit message (massaged for pathname safety) as
the filename. With the --numbered-files option, the output file names
will only be numbers, without the first line of the commit appended.
The names of the output files are printed to standard
output, unless the --stdout option is specified.
If -o is specified, output files are created in <dir>. Otherwise
they are created in the current working directory. The default path
can be set with the format.outputDirectory configuration option.
The -o option takes precedence over format.outputDirectory.
To store patches in the current working directory even when
format.outputDirectory points elsewhere, use -o .. All directory
components will be created.
By default, the subject of a single patch is "[PATCH] " followed by
the concatenation of lines from the commit message up to the first blank
line (see the DISCUSSION section of git-commit(1)).
When multiple patches are output, the subject prefix will instead be
"[PATCH n/m] ". To force 1/1 to be added for a single patch, use -n.
To omit patch numbers from the subject, use -N.
If given --thread, git-format-patch will generate In-Reply-To and
References headers to make the second and subsequent patch mails appear
as replies to the first mail; this also generates a Message-ID header to
reference.
OPTIONS
-p
--no-stat
-
Generate plain patches without any diffstats.
-U<n>
--unified=<n>
-
Generate diffs with <n> lines of context. The number of context
lines defaults to diff.context or 3 if the configuration variable
is unset. (-U without <n> is silently accepted as a synonym for
-p due to a historical accident).
--output=<file>
-
Output to a specific file instead of stdout.
--output-indicator-new=<char>
--output-indicator-old=<char>
--output-indicator-context=<char>
-
Specify the character used to indicate new, old or context
lines in the generated patch. Normally they are +, - and
' ' respectively.
--indent-heuristic
-
Enable the heuristic that shifts diff hunk boundaries to make patches
easier to read. This is the default.
--no-indent-heuristic
-
Disable the indent heuristic.
--minimal
-
Spend extra time to make sure the smallest possible
diff is produced.
--patience
-
Generate a diff using the "patience diff" algorithm.
--histogram
-
Generate a diff using the "histogram diff" algorithm.
--anchored=<text>
-
Generate a diff using the "anchored diff" algorithm.
This option may be specified more than once.
If a line exists in both the source and destination, exists only once,
and starts with <text>, this algorithm attempts to prevent it from
appearing as a deletion or addition in the output. It uses the "patience
diff" algorithm internally.
--diff-algorithm=(patience|minimal|histogram|myers)
-
Choose a diff algorithm. The variants are as follows:
default
myers
-
The basic greedy diff algorithm. Currently, this is the default.
minimal
-
Spend extra time to make sure the smallest possible diff is
produced.
patience
-
Use "patience diff" algorithm when generating patches.
histogram
-
This algorithm extends the patience algorithm to "support
low-occurrence common elements".
For instance, if you configured the diff.algorithm variable to a
non-default value and want to use the default one, then you
have to use --diff-algorithm=default option.
--stat[=<width>[,<name-width>[,<count>]]]
-
Generate a diffstat. By default, as much space as necessary
will be used for the filename part, and the rest for the graph
part. Maximum width defaults to terminal width, or 80 columns
if not connected to a terminal, and can be overridden by
<width>. The width of the filename part can be limited by
giving another width <name-width> after a comma or by setting
diff.statNameWidth=<name-width>. The width of the graph part can be
limited by using --stat-graph-width=<graph-width> or by setting
diff.statGraphWidth=<graph-width>. Using --stat or
--stat-graph-width affects all commands generating a stat graph,
while setting diff.statNameWidth or diff.statGraphWidth
does not affect git format-patch.
By giving a third parameter <count>, you can limit the output to
the first <count> lines, followed by ... if there are more.
These parameters can also be set individually with --stat-width=<width>,
--stat-name-width=<name-width> and --stat-count=<count>.
--compact-summary
-
Output a condensed summary of extended header information such
as file creations or deletions ("new" or "gone", optionally +l
if it’s a symlink) and mode changes (+x or -x for adding
or removing executable bit respectively) in diffstat. The
information is put between the filename part and the graph
part. Implies --stat.
--numstat
-
Similar to --stat, but shows number of added and
deleted lines in decimal notation and pathname without
abbreviation, to make it more machine friendly. For
binary files, outputs two - instead of saying
0 0.
--shortstat
-
Output only the last line of the --stat format containing total
number of modified files, as well as number of added and deleted
lines.
-X [<param>,...]
--dirstat[=<param>,...]
-
Output the distribution of relative amount of changes for each
sub-directory. The behavior of --dirstat can be customized by
passing it a comma separated list of parameters.
The defaults are controlled by the diff.dirstat configuration
variable (see git-config(1)).
The following parameters are available:
changes
-
Compute the dirstat numbers by counting the lines that have been
removed from the source, or added to the destination. This ignores
the amount of pure code movements within a file. In other words,
rearranging lines in a file is not counted as much as other changes.
This is the default behavior when no parameter is given.
lines
-
Compute the dirstat numbers by doing the regular line-based diff
analysis, and summing the removed/added line counts. (For binary
files, count 64-byte chunks instead, since binary files have no
natural concept of lines). This is a more expensive --dirstat
behavior than the changes behavior, but it does count rearranged
lines within a file as much as other changes. The resulting output
is consistent with what you get from the other --*stat options.
files
-
Compute the dirstat numbers by counting the number of files changed.
Each changed file counts equally in the dirstat analysis. This is
the computationally cheapest --dirstat behavior, since it does
not have to look at the file contents at all.
cumulative
-
Count changes in a child directory for the parent directory as well.
Note that when using cumulative, the sum of the percentages
reported may exceed 100%. The default (non-cumulative) behavior can
be specified with the noncumulative parameter.
- <limit>
-
An integer parameter specifies a cut-off percent (3% by default).
Directories contributing less than this percentage of the changes
are not shown in the output.
Example: The following will count changed files, while ignoring
directories with less than 10% of the total amount of changed files,
and accumulating child directory counts in the parent directories:
--dirstat=files,10,cumulative.
--cumulative
-
Synonym for --dirstat=cumulative.
--dirstat-by-file[=<param>,...]
-
Synonym for --dirstat=files,<param>,....
--summary
-
Output a condensed summary of extended header information
such as creations, renames and mode changes.
--no-renames
-
Turn off rename detection, even when the configuration
file gives the default to do so.
--rename-empty
--no-rename-empty
-
Whether to use empty blobs as rename source.
--full-index
-
Instead of the first handful of characters, show the full
pre- and post-image blob object names on the "index"
line when generating patch format output.
--binary
-
In addition to --full-index, output a binary diff that
can be applied with git-apply.
--abbrev[=<n>]
-
Instead of showing the full 40-byte hexadecimal object
name in diff-raw format output and diff-tree header
lines, show the shortest prefix that is at least <n>
hexdigits long that uniquely refers the object.
In diff-patch output format, --full-index takes higher
precedence, i.e. if --full-index is specified, full blob
names will be shown regardless of --abbrev.
Non default number of digits can be specified with --abbrev=<n>.
-B[<n>][/<m>]
--break-rewrites[=[<n>][/<m>]]
-
Break complete rewrite changes into pairs of delete and
create. This serves two purposes:
It affects the way a change that amounts to a total rewrite of a file
not as a series of deletion and insertion mixed together with a very
few lines that happen to match textually as the context, but as a
single deletion of everything old followed by a single insertion of
everything new, and the number <m> controls this aspect of the -B
option (defaults to 60%). -B/70% specifies that less than 30% of the
original should remain in the result for Git to consider it a total
rewrite (i.e. otherwise the resulting patch will be a series of
deletion and insertion mixed together with context lines).
When used with -M, a totally-rewritten file is also considered as the
source of a rename (usually -M only considers a file that disappeared
as the source of a rename), and the number <n> controls this aspect of
the -B option (defaults to 50%). -B20% specifies that a change with
addition and deletion compared to 20% or more of the file’s size are
eligible for being picked up as a possible source of a rename to
another file.
-M[<n>]
--find-renames[=<n>]
-
Detect renames.
If <n> is specified, it is a threshold on the similarity
index (i.e. amount of addition/deletions compared to the
file’s size). For example, -M90% means Git should consider a
delete/add pair to be a rename if more than 90% of the file
hasn’t changed. Without a % sign, the number is to be read as
a fraction, with a decimal point before it. I.e., -M5 becomes
0.5, and is thus the same as -M50%. Similarly, -M05 is
the same as -M5%. To limit detection to exact renames, use
-M100%. The default similarity index is 50%.
-C[<n>]
--find-copies[=<n>]
-
Detect copies as well as renames. See also --find-copies-harder.
If <n> is specified, it has the same meaning as for -M<n>.
--find-copies-harder
-
For performance reasons, by default, -C option finds copies only
if the original file of the copy was modified in the same
changeset. This flag makes the command
inspect unmodified files as candidates for the source of
copy. This is a very expensive operation for large
projects, so use it with caution. Giving more than one
-C option has the same effect.
-D
--irreversible-delete
-
Omit the preimage for deletes, i.e. print only the header but not
the diff between the preimage and /dev/null. The resulting patch
is not meant to be applied with patch or git apply; this is
solely for people who want to just concentrate on reviewing the
text after the change. In addition, the output obviously lacks
enough information to apply such a patch in reverse, even manually,
hence the name of the option.
When used together with -B, omit also the preimage in the deletion part
of a delete/create pair.
-l<num>
-
The -M and -C options involve some preliminary steps that
can detect subsets of renames/copies cheaply, followed by an
exhaustive fallback portion that compares all remaining
unpaired destinations to all relevant sources. (For renames,
only remaining unpaired sources are relevant; for copies, all
original sources are relevant.) For N sources and
destinations, this exhaustive check is O(N^2). This option
prevents the exhaustive portion of rename/copy detection from
running if the number of source/destination files involved
exceeds the specified number. Defaults to diff.renameLimit.
Note that a value of 0 is treated as unlimited.
-O<orderfile>
-
Control the order in which files appear in the output.
This overrides the diff.orderFile configuration variable
(see git-config(1)). To cancel diff.orderFile,
use -O/dev/null.
The output order is determined by the order of glob patterns in
<orderfile>.
All files with pathnames that match the first pattern are output
first, all files with pathnames that match the second pattern (but not
the first) are output next, and so on.
All files with pathnames that do not match any pattern are output
last, as if there was an implicit match-all pattern at the end of the
file.
If multiple pathnames have the same rank (they match the same pattern
but no earlier patterns), their output order relative to each other is
the normal order.
<orderfile> is parsed as follows:
-
Blank lines are ignored, so they can be used as separators for
readability.
-
Lines starting with a hash ("#") are ignored, so they can be used
for comments. Add a backslash ("\") to the beginning of the
pattern if it starts with a hash.
-
Each other line contains a single pattern.
Patterns have the same syntax and semantics as patterns used for
fnmatch(3) without the FNM_PATHNAME flag, except a pathname also
matches a pattern if removing any number of the final pathname
components matches the pattern. For example, the pattern "foo*bar"
matches "fooasdfbar" and "foo/bar/baz/asdf" but not "foobarx".
--skip-to=<file>
--rotate-to=<file>
-
Discard the files before the named <file> from the output
(i.e. skip to), or move them to the end of the output
(i.e. rotate to). These options were invented primarily for the use
of the git difftool command, and may not be very useful
otherwise.
--relative[=<path>]
--no-relative
-
When run from a subdirectory of the project, it can be
told to exclude changes outside the directory and show
pathnames relative to it with this option. When you are
not in a subdirectory (e.g. in a bare repository), you
can name which subdirectory to make the output relative
to by giving a <path> as an argument.
--no-relative can be used to countermand both diff.relative config
option and previous --relative.
-a
--text
-
Treat all files as text.
--ignore-cr-at-eol
-
Ignore carriage-return at the end of line when doing a comparison.
--ignore-space-at-eol
-
Ignore changes in whitespace at EOL.
-b
--ignore-space-change
-
Ignore changes in amount of whitespace. This ignores whitespace
at line end, and considers all other sequences of one or
more whitespace characters to be equivalent.
-w
--ignore-all-space
-
Ignore whitespace when comparing lines. This ignores
differences even if one line has whitespace where the other
line has none.
--ignore-blank-lines
-
Ignore changes whose lines are all blank.
-I<regex>
--ignore-matching-lines=<regex>
-
Ignore changes whose all lines match <regex>. This option may
be specified more than once.
--inter-hunk-context=<number>
-
Show the context between diff hunks, up to the specified <number>
of lines, thereby fusing hunks that are close to each other.
Defaults to diff.interHunkContext or 0 if the config option
is unset.
-W
--function-context
-
Show whole function as context lines for each change.
The function names are determined in the same way as
git diff works out patch hunk headers (see "Defining a
custom hunk-header" in gitattributes(5)).
--ext-diff
-
Allow an external diff helper to be executed. If you set an
external diff driver with gitattributes(5), you need
to use this option with git-log(1) and friends.
--no-ext-diff
-
Disallow external diff drivers.
--textconv
--no-textconv
-
Allow (or disallow) external text conversion filters to be run
when comparing binary files. See gitattributes(5) for
details. Because textconv filters are typically a one-way
conversion, the resulting diff is suitable for human
consumption, but cannot be applied. For this reason, textconv
filters are enabled by default only for git-diff(1) and
git-log(1), but not for git-format-patch(1) or
diff plumbing commands.
--ignore-submodules[=(none|untracked|dirty|all)]
-
Ignore changes to submodules in the diff generation. all is the default.
Using none will consider the submodule modified when it either contains
untracked or modified files or its HEAD differs from the commit recorded
in the superproject and can be used to override any settings of the
ignore option in git-config(1) or gitmodules(5). When
untracked is used submodules are not considered dirty when they only
contain untracked content (but they are still scanned for modified
content). Using dirty ignores all changes to the work tree of submodules,
only changes to the commits stored in the superproject are shown (this was
the behavior until 1.7.0). Using all hides all changes to submodules.
--src-prefix=<prefix>
-
Show the given source <prefix> instead of "a/".
--dst-prefix=<prefix>
-
Show the given destination <prefix> instead of "b/".
--no-prefix
-
Do not show any source or destination prefix.
--default-prefix
-
Use the default source and destination prefixes ("a/" and "b/").
This overrides configuration variables such as format.noprefix,
diff.srcPrefix, diff.dstPrefix, and diff.mnemonicPrefix
(see git-config(1)).
--line-prefix=<prefix>
-
Prepend an additional <prefix> to every line of output.
--ita-invisible-in-index
-
By default entries added by git add -N appear as an existing
empty file in git diff and a new file in git diff --cached.
This option makes the entry appear as a new file in git diff
and non-existent in git diff --cached. This option could be
reverted with --ita-visible-in-index. Both options are
experimental and could be removed in future.
--max-depth=<depth>
-
For each pathspec given on command line, descend at most <depth>
levels of directories. A value of -1 means no limit.
Cannot be combined with wildcards in the pathspec.
Given a tree containing foo/bar/baz, the following list shows the
matches generated by each set of options:
-
--max-depth=0 -- foo: foo
-
--max-depth=1 -- foo: foo/bar
-
--max-depth=1 -- foo/bar: foo/bar/baz
-
--max-depth=1 -- foo foo/bar: foo/bar/baz
-
--max-depth=2 -- foo: foo/bar/baz
If no pathspec is given, the depth is measured as if all
top-level entries were specified. Note that this is different
than measuring from the root, in that --max-depth=0 would
still return foo. This allows you to still limit depth while
asking for a subset of the top-level entries.
Note that this option is only supported for diffs between tree objects,
not against the index or working tree.
For more detailed explanation on these common options, see also
gitdiffcore(7).
-<n>
-
Prepare patches from the topmost <n> commits.
-o <dir>
--output-directory=<dir>
-
Use <dir> to store the resulting files, instead of the
current working directory.
-n
--numbered
-
Name output in [PATCH n/m] format, even with a single patch.
-N
--no-numbered
-
Name output in [PATCH] format.
--start-number <n>
-
Start numbering the patches at <n> instead of 1.
--numbered-files
-
Output file names will be a simple number sequence
without the default first line of the commit appended.
-k
--keep-subject
-
Do not strip/add [PATCH] from the first line of the
commit log message.
-s
--signoff
-
Add a Signed-off-by trailer to the commit message, using
the committer identity of yourself.
See the signoff option in git-commit(1) for more information.
--stdout
-
Print all commits to the standard output in mbox format,
instead of creating a file for each one.
--attach[=<boundary>]
-
Create multipart/mixed attachment, the first part of
which is the commit message and the patch itself in the
second part, with Content-Disposition: attachment.
--no-attach
-
Disable the creation of an attachment, overriding the
configuration setting.
--inline[=<boundary>]
-
Create multipart/mixed attachment, the first part of
which is the commit message and the patch itself in the
second part, with Content-Disposition: inline.
--thread[=<style>]
--no-thread
-
Control addition of In-Reply-To and References headers to
make the second and subsequent mails appear as replies to the
first. Also controls generation of the Message-ID header to
reference.
The optional <style> argument can be either shallow or deep.
shallow threading makes every mail a reply to the head of the
series, where the head is chosen from the cover letter, the
--in-reply-to, and the first patch mail, in this order. deep
threading makes every mail a reply to the previous one.
The default is --no-thread, unless the format.thread configuration
is set. --thread without an argument is equivalent to --thread=shallow.
Beware that the default for git send-email is to thread emails
itself. If you want git format-patch to take care of threading, you
will want to ensure that threading is disabled for git send-email.
--in-reply-to=<message-id>
-
Make the first mail (or all the mails with --no-thread) appear as a
reply to the given <message-id>, which avoids breaking threads to
provide a new patch series.
--ignore-if-in-upstream
-
Do not include a patch that matches a commit in
<until>..<since>. This will examine all patches reachable
from <since> but not from <until> and compare them with the
patches being generated, and any patch that matches is
ignored.
--always
-
Include patches for commits that do not introduce any change,
which are omitted by default.
--cover-from-description=<mode>
-
Control which parts of the cover letter will be automatically
populated using the branch’s description.
<mode> can have the following values:
message
default
-
the cover letter subject will be
populated with placeholder text. The body of the cover letter will be
populated with the branch’s description. This is the default mode when
no configuration nor command line option is specified.
subject
-
the first paragraph of the branch description will
populate the cover letter subject. The remainder of the description will
populate the body of the cover letter.
auto
-
if the first paragraph of the branch description
is greater than 100 bytes, then the mode will be message, otherwise
subject will be used.
none
-
both the cover letter subject and body will be
populated with placeholder text.
--description-file=<file>
-
Use the contents of <file> instead of the branch’s description
for generating the cover letter.
--subject-prefix=<subject-prefix>
-
Use [<subject-prefix>] instead of the standard [PATCH]
prefix in the subject line. This can be used to name a patch
series, and can be combined with the --numbered option.
The configuration variable format.subjectPrefix may also be used
to configure a subject prefix to apply to a given repository for
all patches. This is often useful on mailing lists which receive
patches for several repositories and can be used to disambiguate
the patches (with a value of e.g. "PATCH my-project").
--filename-max-length=<n>
-
Instead of the standard 64 bytes, chomp the generated output
filenames at around <n> bytes (too short a value will be
silently raised to a reasonable length). Defaults to the
value of the format.filenameMaxLength configuration
variable, or 64 if unconfigured.
--rfc[=<rfc>]
-
Prepends the string <rfc> (defaults to "RFC") to
the subject prefix. As the subject prefix defaults to
"PATCH", you’ll get "RFC PATCH" by default.
RFC means "Request For Comments"; use this when sending
an experimental patch for discussion rather than application.
"--rfc=WIP" may also be a useful way to indicate that a patch
is not complete yet ("WIP" stands for "Work In Progress").
If the convention of the receiving community for a particular extra
string is to have it after the subject prefix, the string <rfc>
can be prefixed with a dash ("-") to signal that the rest of
the <rfc> string should be appended to the subject prefix instead,
e.g., --rfc='-(WIP)' results in "PATCH (WIP)".
-v <n>
--reroll-count=<n>
-
Mark the series as the <n>-th iteration of the topic. The
output filenames have v<n> prepended to them, and the
subject prefix ("PATCH" by default, but configurable via the
--subject-prefix option) has v<n> appended to it. E.g.
--reroll-count=4 may produce v4-0001-add-makefile.patch
file that has "Subject: [PATCH v4 1/20] Add makefile" in it.
<n> does not have to be an integer (e.g. --reroll-count=4.4,
or --reroll-count=4rev2 are allowed), but the downside of
using such a reroll-count is that the range-diff/interdiff
with the previous version does not state exactly which
version the new iteration is compared against.
--to=<email>
-
Add a To: header to the email headers. This is in addition
to any configured headers, and may be used multiple times.
The negated form --no-to discards all To: headers added so
far (from config or command line).
--cc=<email>
-
Add a Cc: header to the email headers. This is in addition
to any configured headers, and may be used multiple times.
The negated form --no-cc discards all Cc: headers added so
far (from config or command line).
--from
--from=<ident>
-
Use <ident> in the From: header of each email. In case of a
commit email, if the author ident of the commit is not textually
identical to the provided <ident>, place a From: header in the
body of the message with the original author. If no <ident> is
given, or if the option is not passed at all, use the ident of
the current committer.
Note that this option is only useful if you are actually sending the
emails and want to identify yourself as the sender, but retain the
original author (and git am will correctly pick up the in-body
header). Note also that git send-email already handles this
transformation for you, and this option should not be used if you are
feeding the result to git send-email.
--force-in-body-from
--no-force-in-body-from
-
With the e-mail sender specified via the --from option, by
default, an in-body "From:" to identify the real author of
the commit is added at the top of the commit log message if
the sender is different from the author. With this option,
the in-body "From:" is added even when the sender and the
author have the same name and address, which may help if the
mailing list software mangles the sender’s identity.
Defaults to the value of the format.forceInBodyFrom
configuration variable.
--add-header=<header>
-
Add an arbitrary header to the email headers. This is in addition
to any configured headers, and may be used multiple times.
For example, --add-header="Organization: git-foo".
The negated form --no-add-header discards all (To:,
Cc:, and custom) headers added so far from config or command
line.
--cover-letter
--no-cover-letter
-
In addition to the patches, generate a cover letter file containing the
branch description, commit list and the overall diffstat. You can fill
in a description in the file before sending it out.
--commit-list-format=<format-spec>
-
Specify the format in which to generate the commit list of the patch
series. The accepted values for format-spec are shortlog, modern or
a format-string prefixed with log:. E.g. log: %s (%an).
modern is the same as log:%w(72)[%(count)/%(total)] %s.
The log: prefix can be omitted if the format-string has a % in it
(expecting that it is part of %<placeholder>).
Defaults to the format.commitListFormat configuration variable, if
set, or shortlog.
This option given from the command-line implies the use of
--cover-letter unless --no-cover-letter is given.
--encode-email-headers
--no-encode-email-headers
-
Encode email headers that have non-ASCII characters with
"Q-encoding" (described in RFC 2047), instead of outputting the
headers verbatim. Defaults to the value of the
format.encodeEmailHeaders configuration variable.
--interdiff=<previous>
-
As a reviewer aid, insert an interdiff into the cover letter,
or as commentary of the lone patch of a 1-patch series, showing
the differences between the previous version of the patch series and
the series currently being formatted. <previous> is a single revision
naming the tip of the previous series which shares a common base with
the series being formatted (for example git format-patch
--cover-letter --interdiff=feature/v1 -3 feature/v2).
--range-diff=<previous>
-
As a reviewer aid, insert a range-diff (see git-range-diff(1))
into the cover letter, or as commentary of the lone patch of a
1-patch series, showing the differences between the previous
version of the patch series and the series currently being formatted.
<previous> can be a single revision naming the tip of the previous
series if it shares a common base with the series being formatted (for
example git format-patch --cover-letter --range-diff=feature/v1 -3
feature/v2), or a revision range if the two versions of the series are
disjoint (for example git format-patch --cover-letter
--range-diff=feature/v1~3..feature/v1 -3 feature/v2).
Note that diff options passed to the command affect how the primary
product of format-patch is generated, and they are not passed to
the underlying range-diff machinery used to generate the cover-letter
material (this may change in the future).
--creation-factor=<percent>
-
Used with --range-diff, tweak the heuristic which matches up commits
between the previous and current series of patches by adjusting the
creation/deletion cost fudge factor. See git-range-diff(1))
for details.
Defaults to 999 (the git-range-diff(1) uses 60), as the use
case is to show comparison with an older iteration of the same
topic and the tool should find more correspondence between the two
sets of patches.
--range-diff-notes=<ref>
--no-range-diff-notes
-
Used with --range-diff, tweak what notes to display in the
range diff.
The default behavior is to display the same notes in the range diff as
on the patches; see --notes. Use --range-diff-notes=<ref> to use
<ref> for the range diff instead. This option can be given multiple
times to show notes from multiple refs. Use --no-range-diff-notes to
disable notes in the range diff.
--notes[=<ref>]
--no-notes
-
Append the notes (see git-notes(1)) for the commit
after the three-dash line.
The expected use case of this is to write supporting explanation for
the commit that does not belong to the commit log message proper,
and include it with the patch submission. While one can simply write
these explanations after format-patch has run but before sending,
keeping them as Git notes allows them to be maintained between versions
of the patch series (but see the discussion of the notes.rewrite
configuration options in git-notes(1) to use this workflow).
The default is --no-notes, unless the format.notes configuration is
set.
--signature=<signature>
--no-signature
-
Add a signature to each message produced. Per RFC 3676 the signature
is separated from the body by a line with "-- " on it. If the
signature option is omitted the signature defaults to the Git version
number.
--signature-file=<file>
-
Works just like --signature except the signature is read from a file.
--suffix=.<sfx>
-
Instead of using .patch as the suffix for generated
filenames, use specified suffix. A common alternative is
--suffix=.txt. Leaving this empty will remove the .patch
suffix.
Note that the leading character does not have to be a dot; for example,
you can use --suffix=-patch to get 0001-description-of-my-change-patch.
-q
--quiet
-
Do not print the names of the generated files to standard output.
--no-binary
-
Do not output contents of changes in binary files, instead
display a notice that those files changed. Patches generated
using this option cannot be applied properly, but they are
still useful for code review.
--zero-commit
-
Output an all-zero hash in each patch’s From header instead
of the hash of the commit.
--no-base
--base[=<commit>]
-
Record the base tree information to identify the state the
patch series applies to. See the
BASE TREE INFORMATION section
below for details. If <commit> is auto, a base commit is
automatically chosen. The --no-base option overrides a
format.useAutoBase configuration.
--root
-
Treat the revision argument as a <revision-range>, even if it
is just a single commit (that would normally be treated as a
<since>). Note that root commits included in the specified
range are always formatted as creation patches, independently
of this flag.
--progress
-
Show progress reports on stderr as patches are generated.
CONFIGURATION
You can specify extra mail header lines to be added to each message,
defaults for the subject prefix and file suffix, number patches when
outputting more than one patch, add "To:" or "Cc:" headers, configure
attachments, change the patch output directory, and sign off patches
with configuration variables.
[format]
headers = "Organization: git-foo\n"
subjectPrefix = CHANGE
suffix = .txt
numbered = auto
to = <email>
cc = <email>
attach [ = mime-boundary-string ]
signOff = true
outputDirectory = <directory>
coverLetter = auto
commitListFormat = shortlog
coverFromDescription = auto
DISCUSSION
The patch produced by git format-patch is in UNIX mailbox format,
with a fixed "magic" time stamp to indicate that the file is output
from format-patch rather than a real mailbox, like so:
From 8f72bad1baf19a53459661343e21d6491c3908d3 Mon Sep 17 00:00:00 2001
From: Tony Luck <[email protected]>
Date: Tue, 13 Jul 2010 11:42:54 -0700
Subject: [PATCH] =?UTF-8?q?[IA64]=20Put=20ia64=20config=20files=20on=20the=20?=
=?UTF-8?q?Uwe=20Kleine-K=C3=B6nig=20diet?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
arch/arm config files were slimmed down using a python script
(See commit c2330e286f68f1c408b4aa6515ba49d57f05beae comment)
Do the same for ia64 so we can have sleek & trim looking
...
Typically it will be placed in a MUA’s drafts folder, edited to add
timely commentary that should not go in the changelog after the three
dashes, and then sent as a message whose body, in our example, starts
with "arch/arm config files were…". On the receiving end, readers
can save interesting patches in a UNIX mailbox and apply them with
git-am(1).
When a patch is part of an ongoing discussion, the patch generated by
git format-patch can be tweaked to take advantage of the git am
--scissors feature. After your response to the discussion comes a
line that consists solely of "-- >8 --" (scissors and perforation),
followed by the patch with unnecessary header fields removed:
...
> So we should do such-and-such.
Makes sense to me. How about this patch?
-- >8 --
Subject: [IA64] Put ia64 config files on the Uwe Kleine-König diet
arch/arm config files were slimmed down using a python script
...
When sending a patch this way, most often you are sending your own
patch, so in addition to the "From $SHA1 $magic_timestamp" marker you
should omit From: and Date: lines from the patch file. The patch
title is likely to be different from the subject of the discussion the
patch is in response to, so it is likely that you would want to keep
the Subject: line, like the example above.
Checking for patch corruption
Many mailers if not set up properly will corrupt whitespace. Here are
two common types of corruption:
One way to test if your MUA is set up correctly is:
-
Send the patch to yourself, exactly the way you would, except
with To: and Cc: lines that do not contain the list and
maintainer address.
-
Save that patch to a file in UNIX mailbox format. Call it a.patch,
say.
-
Apply it:
$ git fetch <project> master:test-apply
$ git switch test-apply
$ git restore --source=HEAD --staged --worktree :/
$ git am a.patch
If it does not apply correctly, there can be various reasons.
-
The patch itself does not apply cleanly. That is bad but
does not have much to do with your MUA. You might want to rebase
the patch with git-rebase(1) before regenerating it in
this case.
-
The MUA corrupted your patch; "am" would complain that
the patch does not apply. Look in the .git/rebase-apply/ subdirectory and
see what patch file contains and check for the common
corruption patterns mentioned above.
-
While at it, check the info and final-commit files as well.
If what is in final-commit is not exactly what you would want to
see in the commit log message, it is very likely that the
receiver would end up hand editing the log message when applying
your patch. Things like "Hi, this is my first patch.\n" in the
patch e-mail should come after the three-dash line that signals
the end of the commit message.
MUA-SPECIFIC HINTS
Here are some hints on how to successfully submit patches inline using
various mailers.
GMail
GMail does not have any way to turn off line wrapping in the web
interface, so it will mangle any emails that you send. You can however
use git send-email and send your patches through the GMail SMTP server, or
use any IMAP email client to connect to the google IMAP server and forward
the emails through that.
For hints on using git send-email to send your patches through the
GMail SMTP server, see the EXAMPLE section of git-send-email(1).
For hints on submission using the IMAP interface, see the EXAMPLE
section of git-imap-send(1).
Thunderbird
By default, Thunderbird will both wrap emails as well as flag
them as being format=flowed, both of which will make the
resulting email unusable by Git.
There are three different approaches: use an add-on to turn off line wraps,
configure Thunderbird to not mangle patches, or use
an external editor to keep Thunderbird from mangling the patches.
Approach #1 (add-on)
Install the Toggle Line Wrap add-on that is available from
https://addons.thunderbird.net/thunderbird/addon/toggle-line-wrap
It adds a button "Line Wrap" to the composer’s toolbar
that you can tick off. Now you can compose the message as you otherwise do
(cut + paste, git format-patch | git imap-send, etc), but you have to
insert line breaks manually in any text that you type.
As a bonus feature, the add-on can detect patch text in the composer
and warns when line wrapping has not yet been turned off.
The add-on requires a few tweaks of the advanced configuration
(about:config). These are listed on the download page.
Approach #2 (configuration)
-
Configure your mail server composition as plain text:
Edit…Account Settings…Composition & Addressing,
uncheck "Compose Messages in HTML".
-
Configure your general composition window to not wrap.
In Thunderbird 2:
Edit..Preferences..Composition, wrap plain text messages at 0
In Thunderbird 3:
Edit..Preferences..Advanced..Config Editor. Search for
"mail.wrap_long_lines".
Toggle it to make sure it is set to false. Also, search for
"mailnews.wraplength" and set the value to 0.
-
Disable the use of format=flowed:
Edit..Preferences..Advanced..Config Editor. Search for
"mailnews.send_plaintext_flowed".
Toggle it to make sure it is set to false.
After that is done, you should be able to compose email as you
otherwise would (cut + paste, git format-patch | git imap-send, etc),
and the patches will not be mangled.
Approach #3 (external editor)
-
Prepare the patch as a text file using your method of choice.
-
Before opening a compose window, use Edit→Account Settings to
uncheck the "Compose messages in HTML format" setting in the
"Composition & Addressing" panel of the account to be used to
send the patch.
-
In the main Thunderbird window, before you open the compose
window for the patch, use Tools→about:config to set the
following to the indicated values:
mailnews.send_plaintext_flowed => false
mailnews.wraplength => 0
-
Open a compose window and click the external editor icon.
-
In the external editor window, read in the patch file and exit
the editor normally.
Side note: it may be possible to do step 2 with
about:config and the following settings but no one’s tried yet.
mail.html_compose => false
mail.identity.default.compose_html => false
mail.identity.id?.compose_html => false
There is a script in contrib/thunderbird-patch-inline which can help
you include patches with Thunderbird in an easy way. To use it, do the
steps above and then use the script as the external editor.
KMail
This should help you to submit patches inline using KMail.
-
Prepare the patch as a text file.
-
Click on New Mail.
-
Go under "Options" in the Composer window and be sure that
"Word wrap" is not set.
-
Use Message → Insert file… and insert the patch.
-
Back in the compose window: add whatever other text you wish to the
message, complete the addressing and subject fields, and press send.
BASE TREE INFORMATION
The base tree information block is used for maintainers or third party
testers to know the exact state the patch series applies to. It consists
of the "base commit", which is a well-known commit that is part of the
stable part of the project history everybody else works off of, and zero
or more "prerequisite patches", which are well-known patches in flight
that is not yet part of the "base commit" that need to be applied on top
of "base commit" in topological order before the patches can be applied.
The "base commit" is shown as "base-commit: " followed by the 40-hex of
the commit object name. A "prerequisite patch" is shown as
"prerequisite-patch-id: " followed by the 40-hex "patch id", which can
be obtained by passing the patch through the git patch-id --stable
command.
Imagine that on top of the public commit P, you applied well-known
patches X, Y and Z from somebody else, and then built your three-patch
series A, B, C, the history would be like:
---P---X---Y---Z---A---B---C
With git format-patch --base=P -3 C (or variants thereof, e.g. with
--cover-letter or using Z..C instead of -3 C to specify the
range), the base tree information block is shown at the end of the
first message the command outputs (either the first patch, or the
cover letter), like this:
base-commit: P
prerequisite-patch-id: X
prerequisite-patch-id: Y
prerequisite-patch-id: Z
For non-linear topology, such as
---P---X---A---M---C
\ /
Y---Z---B
You can also use git format-patch --base=P -3 C to generate patches
for A, B and C, and the identifiers for P, X, Y, Z are appended at the
end of the first message.
If set --base=auto in cmdline, it will automatically compute
the base commit as the merge base of tip commit of the remote-tracking
branch and revision-range specified in cmdline.
For a local branch, you need to make it to track a remote branch by git branch
--set-upstream-to before using this option.
EXAMPLES
-
Extract commits between revisions R1 and R2, and apply them on top of
the current branch using git am to cherry-pick them:
$ git format-patch -k --stdout R1..R2 | git am -3 -k
-
Extract all commits which are in the current branch but not in the
origin branch:
$ git format-patch origin
For each commit a separate file is created in the current directory.
-
Extract all commits that lead to origin since the inception of the
project:
$ git format-patch --root origin
-
The same as the previous one:
$ git format-patch -M -B origin
Additionally, it detects and handles renames and complete rewrites
intelligently to produce a renaming patch. A renaming patch reduces
the amount of text output, and generally makes it easier to review.
Note that non-Git patch programs won’t understand renaming patches, so
use it only when you know the recipient uses Git to apply your patch.
-
Extract three topmost commits from the current branch and format them
as e-mailable patches:
CAVEATS
Note that format-patch will omit merge commits from the output, even
if they are part of the requested range. A simple "patch" does not
include enough information for the receiving end to reproduce the same
merge commit.
PATCH APPLICATION
The output from git-format-patch(1) can lead to a different
commit message when applied with git-am(1). The patch that is
applied may also be different from the one that was generated, or patch
application may fail outright.
Any line that is of the form:
-
three-dashes and end-of-line, or
-
a line that begins with diff -, or
-
a line that begins with `Index: `
is taken as the beginning of a patch, and the commit log message
is terminated before the first occurrence of such a line.
Note that this is especially problematic for unindented diffs that occur
in the commit message; the diff in the commit message might get applied
along with the patch section, or the patch application machinery might
trip up because the patch target doesn’t apply. This could for example
be caused by a diff in a Markdown code block.
The solution for this is to indent the diff or other text that could
cause problems.
This loss of fidelity might be simple to notice if you are applying
patches directly from a mailbox. However, changes originating from Git
could be applied in bulk, in which case this would be much harder to
notice. This could for example be a Linux distribution which uses patch
files to apply changes on top of the commits from the upstream
repositories. This goes to show that this behavior does not only impact
email workflows.
Given these limitations, one might be tempted to use a general-purpose
utility like patch(1) instead. However, patch(1) will not only look for
unindented diffs (like git-am(1)) but will try to apply indented
diffs as well.
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